The present invention relates to an apparatus for inspecting tubular textile goods, and to a method for inspecting tubular textile goods. More particularly, the present invention relates to an apparatus for and method of inspecting tubular textile goods by simultaneously inspecting the entire surface area of a portion defined along the length of the tubular textile goods while they are being longitudinally advanced so that inspection can be completely carried out with one pass of the tubular textile goods past an observer.
Modern high speed textile machines produce tubular textile goods, including both knitted goods and woven goods. These tubular textile goods are handle by rolling them up in a flattened web-like condition. When rolled up, the tubular textile goods are similar to an elongated web of material comprised of two layers or two plies.
Various methods of inspecting tubular textile goods after they have been rolled up in a flattened web-like configuration are known. According to one method the roll is placed in a cradle which is positioned at the upper end of an inclined table. The textile goods are then unrolled and advanced in a flattened configuration down the inclined table and are collected at the lower end of the table and stacked in a zig-zag or fan folded configuration. As the textile goods pass along the table the upper side of the textile goods are inspected by an observer, or are sensed by a camera that transmits signals to an appropriate control member for controlling the advancing of the flattened textile goods along the table.
When all of the textile goods have been unrolled, advanced along the table and inspected, and stacked the stack of folded textile goods is then placed in the cradle and the textile goods are again advanced along the table for inspection. This time, however, the opposite side of the flattened textile goods faces the observer so that the entire surface area of the textile goods is inspected.
The previously described method requires that the textile goods pass by the observer twice so that the entire surface area of the flattened textile goods can be inspected. If the entire surface of the textile goods could be inspected with a single pass of the textile goods by the observer the rate at which the the textile goods could be inspected would be substantially increased with an attendant decrease in the cost of inspection. Moreover, the inspection would be more thorough if the two layers of the flattened textile goods could be separated by a member having a colour contrasting with the colour of the textile goods. With the flattened textile goods comprising two layers, a flaw in the upper layer being observed may be difficult to detect because the lower layer has the same colour as the upper layer. A member having a colour contrasting with that of the flattened textile goods and disposed between the two layers would enhance the visibility of flaws and permit a more thorough inspection.
An apparatus which partially solves the problem of eliminating the requirement for two passes of the flattened textile goods in order to completely inspect the same is disclosed in British Pat. No. 928,405 which discloses "Improvements in or relating to the inspection of circular-knitted fabric". The disclosed apparatus includes a frame with an arbor for carrying a roll of tubular textile goods wound thereon in a flattened web-like configuration. Guide rollers mounted on the frame guide the textile goods, which remain in a web-like configuration, to a pair of opposed driven draw rollers. The flattened textile goods pass between the pair of draw rollers which are driven to longitudinally advance the flattened textile goods and unroll them. The apparatus further comprises a casing position along the path of advance of the flattened textile goods and supported on a pair of columns. The flattened textile goods pass over the casing before they reach the pair of opposed draw rollers. The casing is transparent and houses flourescent lamps which illuminate the flattened textile goods from within to enhance the visibility of flaws. Moreover, by using a mirror positioned relative to the casing it is possible for a single observer to simultaneously inspect both sides of the flattened textile goods as they pass over the casing and therefore eliminate the requirement of more than one pass of the flattened textile goods by the observer in order to completely inspect the entire surface of the flattened textile goods.
In the patented apparatus the casing is supported by a pair of columns which extend from the frame up to the casing and which extend along a path of advance of the textile goods. Therefore, after the flattened textile goods have passed over the casing and between the draw rollers they pass over and completely surround the columns supporting the casing. Consequently, to remove the textile goods from the apparatus after inspection has been completed it is necessary to advance the textile goods in the opposite direction from which they were previously advanced to pass them back between the pair of draw rollers and over the casing. Although an observer does not have to continually watch the textile goods as they are being advanced in the reverse direction so that the textile goods can be advanced in the reverse direction at a higher speed than that at which they were advanced during inspection, an operator must still attend to this operation and it is time consuming. The elimination of the requirement to advance the textile goods in the reverse direction before they can be removed from the inspection apparatus would result in further savings of time and money and would therefore be very desirable.